1. Field of the Invention
This invention pertains to steering control systems and more particularly to steering control systems for use with remote controlled transportation units. Most particularly the present invention relates to a steering control system for remote controlled transportation units which are movable along guide lines fixed in space, which units have in each case two drive wheels and possibly additional non-driven wheels, each drive wheel having associated therewith at least one antenna which is movable with the drive wheel and cooperates with one of the guidelines to pick up control signals issuing therefrom.
2. Prior Art
The applicant has already proposed a steering control system for remote controlled transportation in which each transportation unit is provided with two drive wheels which can be guided along a single guide line which is fixed in space. The steering control system is so developed that in each case the leading drive wheel, which is controlled by the guide line, is connected as control wheel while the lagging wheel is connected as slave wheel.
In order to increase the maneuverability of the transportation units, and in particular to improve travel around even sharp curves, internal unpublished studies with transportation units have already been carried out in which the two simultaneously driven drive wheels are controlled by two separate guide lines. In these experiments, however, difficulties arose, particularly in connection with both controlling travel around curves and with lateral displacements occurring oblique to the straight-ahead direction.
The difficulties arose from the fact that when the drive speeds of the driven wheels are not precisely controlled there is an undesired turning or shifting of the entire transport unit which leads to the transport unit moving entirely out of the region in which the remote control is active.
The object of the present invention is therefore to disclose a steering control system of the type mentioned above wherein each transportation unit is self-regulated whereby to correct deviations from the desired direction of travel.